Will behavioral treatments for cognitive impairment in multiple sclerosis become standards-of-care?

Virtual Reality Technology for Physical and Cognitive Function Rehabilitation in People With Multiple Sclerosis

Virtual reality (VR) has significantly expanded the possibilities of medical treatment, particularly in the realm of rehabilitation. VR utilizes advanced technologies to create simulated environments that users perceive as analogous to the real world. Researchers have demonstrated that VR can effectively train motor, sensory, and cognitive functions. This manuscript offers a concise review of recent evidence concerning the effects of VR training on key clinical symptoms in people with multiple sclerosis (pwMS), with the aim of highlighting VR's potential as a complementary rehabilitative tool for improving ubiquitous symptoms of multiple sclerosis (MS)-a neurodegenerative, often disabling, disease. In addition to presenting a brief overview of recent literature on VR for pwMS, this narrative review seeks to provide health professionals with a foundational understanding of VR as a rehabilitative tool in MS. Furthermore, it may aid in identifying gaps in the literature and stimulate the development of new hypotheses and theories regarding the use of VR in patients with a neurodegenerative disease.

Cognitive impairment in multiple sclerosis: from phenomenology to neurobiological mechanisms

Multiple sclerosis (MS) is an autoimmune-mediated disease of the central nervous system characterized by inflammation, demyelination and chronic progressive neurodegeneration. Among its broad and unpredictable range of clinical symptoms, cognitive impairment (CI) is a common and disabling feature greatly affecting the patients' quality of life. Its prevalence is 20% up to 88% with a wide variety depending on the phenotype of MS, with highest frequency and severity in primary progressive MS. Involving different cognitive domains, CI is often associated with depression and other neuropsychiatric symptoms, but usually not correlated with motor and other deficits, suggesting different pathophysiological mechanisms. While no specific neuropathological data for CI in MS are available, modern research has provided evidence that it arises from the disease-specific brain alterations. Multimodal neuroimaging, besides structural changes of cortical and deep subcortical gray and white matter, exhibited dysfunction of fronto-parietal, thalamo-hippocampal, default mode and cognition-related networks, disruption of inter-network connections and involvement of the γ-aminobutyric acid (GABA) system. This provided a conceptual framework to explain how aberrant pathophysiological processes, including oxidative stress, mitochondrial dysfunction, autoimmune reactions and disruption of essential signaling pathways predict/cause specific disorders of cognition. CI in MS is related to multi-regional patterns of cerebral disturbances, although its complex pathogenic mechanisms await further elucidation. This article, based on systematic analysis of PubMed, Google Scholar and Cochrane Library, reviews current epidemiological, clinical, neuroimaging and pathogenetic evidence that could aid early identification of CI in MS and inform about new therapeutic targets and strategies.

Focusing on neural mechanisms of exercise training benefits in multiple sclerosis

Exercise training (ET) should be a mainstay of comprehensive care in multiple sclerosis (MS), yet there is reluctance regarding its implementation among healthcare providers. This reluctance has its roots in the lack of evidence from randomized controlled trials (RCTs) that provide a neurobiological mechanism for beneficial outcomes. We argue that ET training is efficacious for improving mobility and cognitive dysfunction as hallmark consequences of MS, and propose an experimental medicine framework for guiding research focusing on CNS mechanisms-of-action for ET benefits. The framework establishes three hierarchical pathways as preconditions for applying a mediation framework in a fourth pathway for fully testing mechanistic research questions using a RCT. This paper describes the conceptual basis of the pathways, and then reviews the existing evidence within the pathways of the framework for ET effects on the CNS, mobility, and cognition in MS. Lastly, this paper discusses future directions and challenges for testing the pathways of the framework for advancing the evidence regarding CNS mechanisms of ET benefits in this population. Our objective is guiding the field toward evidence that facilitates the prescription and promotion of ET as a neurorestorative approach within MS clinical practice.

A Review on the Feasibility and Efficacy of Home-Based Cognitive Remediation in People with Multiple Sclerosis

Cognitive impairment affects 34-65% of People with Multiple Sclerosis (PwMS), significantly impacting their quality of life. Clinicians routinely address cognitive deficits with in-clinic neuro-behavioural interventions, but accessibility issues exist. Given these challenges, coupled with the lifelong need for continuous assistance in PwMS, researchers have underscored the advantageous role of telerehabilitation in addressing these requirements. Nonetheless, the feasibility and efficacy of home-based cognitive remediation remain to be firmly established. In this narrative review, we aimed to investigate the feasibility and efficacy of digital telerehabilitation for cognition in PwMS. Thirteen relevant studies were identified and carefully assessed. Regarding the feasibility of cognitive telerehabilitation, evidence shows adherence rates are generally good, although, surprisingly, not all studies reported measures of compliance with the cognitive training explored. Considering the efficacy of rehabilitative techniques on cognitive performance in PwMS, findings are generally inconsistent, with only one study reporting uniformly positive results. A range of methodological limitations are reported as potential factors contributing to the variable results. Future research must address these challenges, as more rigorous studies are required to draw definitive conclusions regarding the efficacy of home-based cognitive remediation in PwMS. Researchers must prioritise identifying optimal intervention approaches and exploring the long-term effects of telerehabilitation.

Cognition in vestibular disorders: state of the field, challenges, and priorities for the future

Vestibular disorders are prevalent and debilitating conditions of the inner ear and brain which affect balance, coordination, and the integration of multisensory inputs. A growing body of research has linked vestibular disorders to cognitive problems, most notably attention, visuospatial perception, spatial memory, and executive function. However, the mechanistic bases of these cognitive sequelae remain poorly defined, and there is a gap between our theoretical understanding of vestibular cognitive dysfunction, and how best to identify and manage this within clinical practice. This article takes stock of these shortcomings and provides recommendations and priorities for healthcare professionals who assess and treat vestibular disorders, and for researchers developing cognitive models and rehabilitation interventions. We highlight the importance of multidisciplinary collaboration for developing and evaluating clinically relevant theoretical models of vestibular cognition, to advance research and treatment.

Non-pharmacological randomized intervention trial for the management of neuropsychological symptoms in outpatients with progressive multiple sclerosis

PURPOSE

Despite typically more pronounced cognitive and mental health issues in progressive disease courses of multiple sclerosis (PMS), rehabilitation research in this subgroup is rare. The efficacy of two non-pharmacological interventions with positive results from prior investigations was therefore examined in PMS specifically.

METHODS

Persons with PMS (pwPMS) received either computerized cognitive training (BrainStim), standardized cognitive-behavioral group sessions (Metacognitive Training [MaTiMS]), or a combination of both in an ambulatory setting. Neuropsychological assessment was conducted before and after the four-week intervention.

RESULTS

37 participants (13 with primary/24 with secondary PMS, meanage = 52.87, SDage = 7.11, meanEDSS = 4.02, SDEDSS = 1.35) entered analyses. The BrainStim group improved in immediate and delayed verbal memory, recognition, verbal working memory, and perceived cognitive deficits while experiencing increased anxiety post-intervention. MaTiMS participants reported high program satisfaction and less cognitive difficulties at retest. The Combination group performed better in immediate and delayed verbal memory, and in information processing speed after training. Descriptive data further indicated positive effects on anxiety and depression in the MaTiMS and Combination group.

CONCLUSIONS

While objective cognitive performance improved when explicitly trained, psychoeducative sessions contributed to subjective mental health. The combination of both approaches is thus suggested, considering the specific needs of pwPMS treated in an ambulatory setting.

Cognitive impairment and its treatment in patients with multiple sclerosis

Cognitive impairment (CI) is a relatively common manifestation of multiple sclerosis (MS), which can occur with any type of the disease course and activity. The largest CI prevalence and severity are observed in progressive MS. In relapsing-remitting MS the most prominent deterioration of cognitive functions is seen during relapses; however, in some patients it can continue also throughout remission. In a small number of patients CI can be the most significant symptom of the disease; in addition, it sometimes can be the only clinical feature of the relapse. Despite this, in clinical practice CI remains out of the focus of attention, and is not evaluated when assessing the disease severity and/or activity, while CI is not included into EDSS. Nonetheless, a number of specialized neuropsychological tests and batteries has been developed recently, which can be used for both screening and detailed assessment of CI in MS, as well as for assessment of its changes over time. CI has a negative impact on MS patients' quality of life, their social interactions, daily and occupational activities. The influence of disease-modifying agents on CI has been poorly investigated; however, there is evidence that they can reduce the degree of CI. The optimal choice of pathogenetic treatment in patients with CI remains understudied. There is no convincing evidence of the effectiveness of symptomatic pharmacological treatment of CI in MS, and cognitive rehabilitation is the only approach with confirmed effectiveness. Considering the limitations of this technique (its availability, quite a big number of sessions), there is a need to search for other methods to increase its efficacy, including non-invasive neuromodulation (in particular, transcranial direct current stimulation or transcranial magnetic stimulation). This article is focused on a brief review of the main diagnostic methods of CI in MS, its pathogenetic and symptomatic treatment, and cognitive rehabilitation techniques, as well as on the results of the studies on non-invasive neuromodulation.

Feasibility of remotely delivered and supported aerobic walking exercise training for cognitive processing speed impairment in fully-ambulatory persons with multiple sclerosis

PURPOSE

The current pilot, single-blind, randomized controlled trial (RCT) examined the feasibility of remotely-delivered and supported aerobic walking exercise training compared with an active control condition on cognitive processing speed (CPS) in 19 fully-ambulatory persons with multiple sclerosis (pwMS) who were pre-screened for impaired CPS.

METHODS

Feasibility was assessed in the domains of process (e.g., recruitment), resource (e.g., monetary costs), management (e.g., time requirements), and scientific outcomes (i.e., treatment effect). Fully-ambulatory, but CPS-impaired pwMS were randomly assigned into either 16-weeks of home-based aerobic walking exercise or home-based stretching and range-of-motion activities. Both conditions involved delivery of informational newsletters and one-on-one, online video chats with a behavior coach. Participants across both conditions tracked their activity using highly accurate wearable motion sensors. Treatment-blinded assessors administered the Symbol Digit Modalities Test (SDMT) remotely before and after the 16-week study period.

RESULTS

The study was cost-effective, accessible, and acceptable. The intervention further was safe. Adherence and compliance rates across both conditions exceeded 80%. There was an overall moderate effect for change in SDMT score between the conditions (d = 0.42). The intervention was associated with a 4.8-point improvement in SDMT scores (d = 0.70; 10% increase) compared with a 1-point improvement for the control condition (d = 0.09; 2% increase).

CONCLUSIONS

This remotely-delivered and supported aerobic walking exercise training intervention was safe and feasible for fully-ambulatory, CPS-impaired pwMS. The pattern of results, including the promising effects on CPS, support the design and implementation of an appropriately-powered RCT on this approach for managing CPS impairment in a large MS sample.

Cognitive skill learning in multiple sclerosis: A meaningful component of the neuropsychological profile

Cognitive skill learning (CSL) refers to the capacity to improve performance on specific cognitive operations through repeated practice. We hypothesized that high CSL aptitude may promote accumulation of cognitive reserve, and resiliency to cognitive decline, in people with Multiple Sclerosis (MS). Using an adaptive working memory training paradigm, we obtained CSL aptitude indices (amount of improvement on the training task over time) in MS patients for a single session of practice (25-30 min), and longer-term practice (twenty sessions). Neuropsychological performance was assessed with the Symbol Digit Modalities Test (SDMT), Paced Auditory Serial Addition Test (PASAT), and the Raven's Advanced Progressive Matrices (RAPM). CSL aptitude measures were positively correlated with neuropsychological performance, and had high diagnostic accuracy for classifying cognitive impairment in MS, defined as 1.5 SD below the demographics-corrected normative mean of the SDMT. Positive relationships between CSL aptitude measures and neuropsychological performance tended to be more pronounced for individuals with high estimated cognitive reserve, suggesting that high CSL aptitude is a a factor that promotes the protective effects of cognitive reserve. Furthermore, regression analyses indicated that CSL aptitude is separable from baseline cognitive capacity. The findings suggest that CSL aptitude impacts the neuropsychological profile in MS, and may be a factor underlying variance in cognitive resiliency.

Developing the Rationale for Including Virtual Reality in Cognitive Rehabilitation and Exercise Training Approaches for Managing Cognitive Dysfunction in MS

Cognitive impairment is a common and detrimental consequence of multiple sclerosis (MS) and current rehabilitation methods are insufficient. Cognitive rehabilitation (CR) and exercise training (ET) are the most promising behavioral approaches to mitigate cognitive deficits, but effects are small and do not effectively translate to improvements in everyday function. This article presents a conceptual framework supporting the use of virtual reality (VR) as an ideal, common adjuvant traditional CR and ET in MS. VR could strengthen the effects of CR and ET by increasing sensory input and promoting multisensory integration and processing during rehabilitation. For ET specifically, VR can also help incorporate components of CR into exercise sessions. In addition, VR can enhance the transfer of cognitive improvements to everyday functioning by providing a more ecologically valid training environment. There is a clear interest in adding VR to traditional rehabilitation techniques for neurological populations, a stronger body of evidence of this unique approach is needed in MS. Finally, to better understand how to best utilize VR in rehabilitation for cognitive deficits in MS, more systematic research is needed to better understand the mechanism(s) of action of VR with CR and ET.

A systematic review of resting state functional MRI connectivity changes and cognitive impairment in multiple sclerosis

INTRODUCTION

Cognitive impairment in multiple sclerosis (MS) is increasingly being investigated with resting state functional MRI (rs-fMRI) functional connectivity (FC) . However, results remain difficult to interpret, showing both high and low FC associated with cognitive impairment. We conducted a systematic review of rs-fMRI studies in MS to understand whether the direction of FC change relates to cognitive dysfunction, and how this may be influenced by the choice of methodology.

METHODS

Embase, Medline and PsycINFO were searched for studies assessing cognitive function and rs-fMRI FC in adults with MS.

RESULTS

Fifty-seven studies were included in a narrative synthesis. Of these, 50 found an association between cognitive impairment and FC abnormalities. Worse cognition was linked to high FC in 18 studies, and to low FC in 17 studies. Nine studies found patterns of both high and low FC related to poor cognitive performance, in different regions or for different MR metrics. There was no clear link to increased FC during early stages of MS and reduced FC in later stages, as predicted by common models of MS pathology. Throughout, we found substantial heterogeneity in study methodology, and carefully consider how this may impact on the observed findings.

DISCUSSION

These results indicate an urgent need for greater standardisation in the field - in terms of the choice of MRI analysis and the definition of cognitive impairment. This will allow us to use rs-fMRI FC as a biomarker in future clinical studies, and as a tool to understand mechanisms underpinning cognitive symptoms in MS.

MRI correlates of cognitive improvement after home-based EEG neurofeedback training in patients with multiple sclerosis: a pilot study

OBJECTIVE

Neurofeedback training may improve cognitive function in patients with neurological disorders. However, the underlying cerebral mechanisms of such improvements are poorly understood. Therefore, we aimed to investigate MRI correlates of cognitive improvement after EEG-based neurofeedback training in patients with MS (pwMS).

METHODS

Fourteen pwMS underwent ten neurofeedback training sessions within 3-4 weeks at home using a tele-rehabilitation system. Half of the pwMS (N = 7, responders) learned to self-regulate sensorimotor rhythm (SMR, 12-15 Hz) by visual feedback and improved cognitively after training, whereas the remainder (non-responders, n = 7) did not. Diffusion-tensor imaging and resting-state fMRI of the brain was performed before and after training. We analyzed fractional anisotropy (FA) and functional connectivity (FC) of the default-mode, sensorimotor (SMN) and salience network (SAL).

RESULTS

At baseline, responders and non-responders were comparable regarding sex, age, education, disease duration, physical and cognitive impairment, and MRI parameters. After training, compared to non-responders, responders showed increased FA and FC within the SAL and SMN. Cognitive improvement correlated with increased FC in SAL and a correlation trend with increased FA was observed.

CONCLUSIONS

This exploratory study suggests that successful neurofeedback training may not only lead to cognitive improvement, but also to increases in brain microstructure and functional connectivity.

Training the brain: could it improve multiple sclerosis treatment?

Multiple sclerosis (MS) is a neurological disease characterized by neuroinflammation, demyelination and axonal degeneration along with loss of function in the central nervous system. For many years, research in MS has focused on the efficacy of pharmacological treatments. However, during the last years, many publications have been dedicated to the study of the efficacy of non-pharmacological strategies, such as physical exercise and cognitive training. Beneficial effects of the combination of both strategies on cognitive function have been described in both ageing adults and patients with neurodegenerative diseases, such as MS. The analysis of combining both physical and cognitive stimulation can be summarized by the environmental enrichment (EE) experiments, which are more suitable for animal models. EE refers to housing conditions consisting of exercise and cognitive and social stimulation. In this review, we will summarize the available studies that describe the influence of EE in both MS patients and MS animal models.

[The efficacy of active physical exercises in comprehensive cognitive rehabilitation of pediatric and adult patients with multiple sclerosis]

Cognitive dysfunction in multiple sclerosis (MS) is a disabling factor and extends to the processes of memory, attention, verbal and logical thinking, visual-spatial, and motor skills. 40-70% of patients have a decrease in the rate of information processing, dysfunction of executive functions, and decrease in the quality of training. Cognitive dysfunction is also often reduced quality of life with MS. The most common methods of non-drug cognitive function correction are cognitive rehabilitation and exercise. This article reviews current research on the positive effects of regular physical activity on the cognitive functions of adults and children with MS.

Systematic Review on Exercise Training as a Neuroplasticity-Inducing Behavior in Multiple Sclerosis

Background. Exercise training is associated with functional improvements in persons with multiple sclerosis (MS), perhaps based on neuroplasticity. However, inferences regarding neuroplasticity require observations of exercise-related changes in the central nervous system that explain functional adaptations. This systematic review critically evaluated studies on exercise training, neuroimaging outcomes, and functional outcomes in MS based on consistency with a well-established conceptual model for characterizing exercise training as a possible neuroplasticity-inducing behavior in this population. Methods. We performed targeted and comprehensive searches of multiple databases for papers involving exercise training interventions on functional and neuroimaging outcomes in persons with MS. Acceptable study designs included randomized controlled trials, single-group pre/post designs, and quasi-experimental designs. Four independent reviewers extracted relevant data from each eligible paper on characteristics of participants, exercise interventions, neuroimaging outcomes, functional outcomes, pattern of study results, and potential risks of bias. Results. The literature search returned only 10 papers (involving 8 original interventions) that met eligibility criteria wherein inferences regarding neuroplasticity could be drawn, based on inclusion of neuroimaging and functional endpoints. Within those 10 papers, there is mixed evidence for exercise training as a neuroplasticity-inducing behavior in persons with MS. Conclusions. Such a paucity of evidence supporting exercise-induced neuroplasticity in MS is likely a product of a very small number of papers that do not sufficiently examine hypothesized mechanisms of action. Future research might consider examining specific neural changes that might result from exercise prescriptions that are specifically designed to induce certain functional changes among persons with MS.

Exercise training and cognitive performance in persons with multiple sclerosis: A systematic review and multilevel meta-analysis of clinical trials

BACKGROUND

Cognitive impairment is common, debilitating, and poorly managed in persons with multiple sclerosis (pwMS). Exercise training might have positive effects on cognitive performance in pwMS, yet the overall magnitude, heterogeneity, and potential moderators remain unclear.

OBJECTIVE

This three-level meta-analysis aims to identify the effects of exercise training and those of exercise modalities on global and domain-specific cognitive performance in pwMS.

METHODS

MEDLINE, PsycInfo, SportDiscus, CENTRAL, and EMBASE were screened for randomized and non-randomized clinical trials from inception to 27 January 2020, yielding 3091 articles. Based on titles and abstracts, 75 articles remained in the selection process. After full-text evaluation, 13 studies were finally selected (PROSPERO pre-registered).

RESULTS

The pooled effect of exercise training on the global cognitive performance was null (g = 0.04, 95% confidence interval (CI): -0.11 to 0.18) and no significant differences were displayed among domains. Heterogeneity within studies was null (I(2)2= 0.0%) and between studies was low (I(3)2= 25.1%). None of the moderators (exercise modalities, age, Expanded Disability Status Scale (EDSS), supervision, cognitive domains) reached significance. However, the exercise volume explained most of the overall heterogeneity (slope = 4.651 × 10^-5, R(2)2 = 100%, R(3)2 = 52.34%).

CONCLUSION

These results do not support the efficacy of exercise training on global or domain-specific cognitive performance in pwMS. Future studies are needed to determine whether higher training dose are beneficial.

Treatment and management of cognitive dysfunction in patients with multiple sclerosis

Cognitive impairment is a common and devastating manifestation of multiple sclerosis (MS). Although disease-modifying therapies have been efficacious for reducing relapse rates in MS, such treatments are ineffective for treating cognitive dysfunction. Alternative treatment approaches for mitigating cognitive problems are greatly needed in this population. To date, cognitive rehabilitation and exercise training have been identified as possible candidates for treating MS-related cognitive impairment; however, cognitive dysfunction is still often considered to be poorly managed in patients with MS. This Review provides a comprehensive overview of recent developments in the treatment and management of cognitive impairment in people with MS. We describe the theoretical rationales, current states of the science, field-wide challenges and recent advances in cognitive rehabilitation and exercise training for treating MS-related cognitive impairment. We also discuss future directions for research into the treatment of cognitive impairment in MS that should set the stage for the inclusion of cognitive rehabilitation and exercise training into clinical practice within the next decade.

Cognitive Impairment and Brain Reorganization in MS: Underlying Mechanisms and the Role of Neurorehabilitation

Multiple sclerosis (MS) is a chronic, immune-mediated, inflammatory, and degenerative disease of the central nervous system (CNS) that affects both white and gray matter. Various mechanisms throughout its course, mainly regarding gray matter lesions and brain atrophy, result in cognitive network dysfunction and can cause clinically significant cognitive impairment in roughly half the persons living with MS. Altered cognition is responsible for many negative aspects of patients' lives, independently of physical disability, such as higher unemployment and divorce rates, reduced social activities, and an overall decrease in quality of life. Despite its devastating impact it is not included in clinical ratings and decision making in the way it should be. It is interesting that only half the persons with MS exhibit cognitive dysfunction, as this implies that the other half remain cognitively intact. It appears that a dynamic balance between brain destruction and brain reorganization is taking place. This balance acts in favor of keeping brain systems functioning effectively, but this is not so in all cases, and the effect does not last forever. When these systems collapse, functional brain reorganization is not effective anymore, and clinically apparent impairments are evident. It is therefore important to reveal which factors could make provision for the subpopulation of patients in whom cognitive impairment occurs. Even if we manage to detect this subpopulation earlier, effective pharmaceutical treatments will still be lacking. Nevertheless, recent evidence shows that cognitive rehabilitation and neuromodulation, using non-invasive techniques such as transcranial magnetic or direct current stimulation, could be effective in cognitively impaired patients with MS. In this Mini Review, we discuss the mechanisms underlying cognitive impairment in MS. We also focus on mechanisms of reorganization of cognitive networks, which occur throughout the disease course. Finally, we review theoretical and practical issues of neurorehabilitation and neuromodulation for cognition in MS as well as factors that influence them and prevent them from being widely applied in clinical settings.

Environmental enrichment improves cognitive symptoms and pathological features in a focal model of cortical damage of multiple sclerosis

Multiple Sclerosis (MS) is a neuroinflammatory disease affecting white and grey matter, it is characterized by demyelination, axonal degeneration along with loss of motor, sensitive and cognitive functions. MS is a heterogeneous disease that displays different clinical courses: relapsing/remitting MS (RRMS), and MS progressive forms: primary progressive (PPMS) and secondary progressive (SPMS). Cortical damage in the progressive MS forms has considerable clinical relevance due to its association with cognitive impairment and disability progression in patients. One treatment is available for the progressive forms of the disease, but none are specific for cognitive deficits. We developed an animal model that reflects most of the characteristics of the cortical damage, such as cortical neuroinflammation, demyelination, neurodegeneration and meningeal inflammation, which was associated with cognitive impairment. Cognitive rehabilitation, exercise and social support have begun to be evaluated in patients and animal models of neurodegenerative diseases. Environmental enrichment (EE) provides exercise as well as cognitive and social stimulation. EE has been demonstrated to exert positive effects on cognitive domains, such as learning and memory, and improving anxiety-like symptoms. We proposed to study the effect of EE on peripherally stimulated cortical lesion induced by the long term expression of interleukin IL-1β (IL-1β) in adult rats. Here, we demonstrated that EE: 1) reduces the peripheral inflammatory response to the stimulus, 2) ameliorates cognitive deficits and anxiety-like symptoms, 3) modulates neurodegeneration, demyelination and glial activation, 4) regulates neuroinflammation by reducing the expression of pro-inflammatory cytokines and enhancing the expression of anti-inflammatory ones. Our findings correlate with the fact that EE housing could be considered an effective non- pharmacological therapeutic agent that can synergistically aid in the rehabilitation of the disease.

Protocol for a systematically-developed, phase I/II, single-blind randomized controlled trial of treadmill walking exercise training effects on cognition and brain function in persons with multiple sclerosis

Slowed cognitive processing speed (CPS) is a common and debilitating consequence of multiple sclerosis (MS) that is notoriously difficult to treat. As such, we undertook a systematic line of research that indicated that supervised, progressive treadmill walking exercise (TMWX) training might improve CPS and brain functioning among fully-ambulatory persons with MS. The current study will be the first adequately-powered, single-blind randomized controlled trial (RCT) that examines the efficacy of 12-weeks of TMWX training compared with an active control condition on CPS, thalamocortical brain connectivity (based on resting-state fMRI), and exploratory functional outcomes in 88 fully-ambulatory persons with MS who present with slowed CPS. The intervention condition involves supervised, progressive TMWX training 3 times/week over 12-weeks; this initially involves 15-min of light-to-moderate intensity TMWX that progresses up to 40-min of vigorous intensity TMWX. The active control condition involves supervised, minimal intensity, stretching-and-resistance exercise that will be delivered on the same frequency as the intervention condition. The primary study outcomes involve Symbol Digit Modalities Test performance (i.e., CPS) and fMRI-based measures of thalamocortical resting-state functional connectivity. Exploratory study outcomes involve measures of community participation, activities of daily living, quality of life, and functional mobility. All study outcomes will be administered before and after the 12-week study period by treatment-blinded assessors. If successful, the current study will provide the first Class I evidence for the effects of TMWX training as an approach for improving CPS and its neural correlate, and possibly mitigating the impact of slowed CPS on functional outcomes in MS.

Changes in Cognitive Performance With Age in Adults With Multiple Sclerosis

BACKGROUND

Cognitive impairment is one of the most common consequences of multiple sclerosis (MS), yet there is a shortage of data regarding how cognition changes during the life span of individuals with MS. This information is of increasing importance given the growing proportion of older adults with MS.

OBJECTIVE

To study possible changes in cognitive function in correlation with increasing age in individuals with MS.

METHODS

Participants (N=129) were recruited and a priori allocated into one of three age groups (young, middle-aged, and older). All participants completed the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) during a single laboratory testing session. The BICAMS measures cognitive processing speed as well as verbal and visuospatial learning and memory.

RESULTS

A multivariate analysis of variance indicated that cognitive function significantly differed by age group, and these differences were not explained by amount of physical activity, years of education, years since diagnosis, or race. Older adults displayed significantly worse cognitive processing speed than young and middle-aged adults. The older and middle-aged adults also demonstrated significantly worse visuospatial learning and memory than the younger adults. Effect sizes indicated that cognitive processing speed and verbal learning and memory were more affected in late adulthood than early adulthood, whereas visuospatial learning and memory was affected similarly in early and late adulthood.

CONCLUSIONS

Older adults with MS demonstrated significant impairments in cognitive function compared to young and middle-aged adults with MS. Future studies should determine the predictors of cognitive decline in this age cohort.